Browsing by Author "Duncan, K. J."

Now showing items 21-29 of 29

    • LoTSS/HETDEX: Disentangling star formation and AGN activity in gravitationally-lensed radio-quiet quasars 

      Stacey, H. R.; McKean, J. P.; Jackson, N. J.; Best, P. N.; Rivera, G. Calistro; Callingham, J. R.; Duncan, K. J.; Gürkan, G.; Hardcastle, M. J.; Iacobelli, M.; Mechev, A. P.; Morabito, L. K.; Prandoni, I.; Röttgering, H. J. A.; Sabater, J.; Shimwell, T. W.; Tasse, C.; Williams, W. L. (2018-11-19)
      Determining the star-forming properties of radio-quiet quasars is important for understanding the co-evolution of star formation and black hole accretion. Here, we present the detection of the gravitationally-lensed ...

    • Low frequency radio properties of the $z>5$ quasar population 

      Gloudemans, A. J.; Duncan, K. J.; Röttgering, H. J. A.; Shimwell, T. W.; Venemans, B. P.; Best, P. N.; Brüggen, M.; Rivera, G. Calistro; Drabent, A.; Hardcastle, M. J.; Miley, G. K.; Schwarz, D. J.; Saxena, A.; Smith, D. J. B.; Williams, W. L. (2021-12-31)
      Optically luminous quasars at z > 5 are important probes of super-massive black hole (SMBH) formation. With new and future radio facilities, the discovery of the brightest low-frequency radio sources in this epoch would ...

    • Low-frequency radio spectra of submillimetre galaxies in the Lockman Hole 

      Ramasawmy, J.; Geach, J. E.; Hardcastle, M. J.; Best, P. N.; Bonato, M.; Bondi, M.; Rivera, G. Calistro; Cochrane, R. K.; Conway, J. E.; Coppin, K.; Duncan, K. J.; Dunlop, J. S.; Franco, M.; García-Vergara, C.; Jarvis, M. J.; Kondapally, R.; McCheyne, I.; Prandoni, I.; Röttgering, H. J. A.; Smith, D. J. B.; Tasse, C.; Wang, L. (2021-04-19)
      We investigate the radio properties of a sample of 53 sources selected at 850 $\mu$m from the SCUBA-2 Cosmology Legacy Survey using new deep, low-frequency radio imaging of the Lockman Hole field from the Low Frequency ...

    • No strong radio absorption detected in the low-frequency spectra of radio-loud quasars at z > 5.6 

      Gloudemans, A. J.; Saxena, A.; Intema, H.; Callingham, J. R.; Duncan, K. J.; Rottgering, H. J. A.; Belladitta, S.; Hardcastle, M. J.; Harikane, Y.; Spingola, C. (2023-10-12)
      We present the low-frequency radio spectra of nine high-redshift quasars at 5:6 < z < 6:6 using the Giant Metre Radio Telescope band-3, -4, and -5 observations (∼300-1200 MHz), archival Low Frequency Array (LOFAR; 144 MHz), ...

    • Plausible association of distant late M dwarfs with low-frequency radio emission 

      Gloudemans, A. J.; Callingham, J. R.; Duncan, K. J.; Saxena, A.; Harikane, Y.; Hill, G. J.; Zeimann, G. R.; Rottgering, H. J. A.; Hardcastle, M. J.; Pineda, J. S.; Shimwell, T. W.; Smith, D. J. B.; Wagenveld, J. D. (2023-10-17)
      We present the serendipitous discovery of eight distant (> 50 pc) late M dwarfs with plausible associated radio emission at 144 MHz. The M-dwarf nature of our sources has been confirmed with optical spectroscopy performed ...

    • Radio-loud AGN in the first LoTSS data release: The lifetimes and environmental impact of jet-driven sources 

      Hardcastle, M. J.; Williams, W. L.; Best, P. N.; Croston, J. H.; Duncan, K. J.; Rottgering, H. J. A.; Sabater, J.; Shimwell, T. W.; Tasse, C.; Callingham, J. R.; Cochrane, R. K.; Gasperin, F. de; Gurkan, G.; Jarvis, M. J.; Mahatma, V.; Miley, G. K.; Mingo, B.; Mooney, S.; Morabito, L. K.; O'Sullivan, S. P.; Prandoni, I.; Shulevski, A.; Smith, D. J. B. (2018-11-19)
      We constructed a sample of 23,344 radio-loud active galactic nuclei (RLAGN) from the catalogue derived from the LOFAR Two-Metre Sky Survey (LoTSS) survey of the HETDEX Spring field. Although separating AGN from star-forming ...

    • Revisiting the Fanaroff-Riley dichotomy and radio-galaxy morphology with the LOFAR Two-Metre Sky Survey (LoTSS) 

      Mingo, B.; Croston, J. H.; Hardcastle, M. J.; Best, P. N.; Duncan, K. J.; Morganti, R.; Rottgering, H. J. A.; Sabater, J.; Shimwell, T. W.; Williams, W. L.; Brienza, M.; Gurkan, G.; Mahatma, V. H.; Morabito, L. K.; Prandoni, I.; Bondi, M.; Ineson, J.; Mooney, S. (2019-09-01)
      The relative positions of the high and low surface brightness regions of radio-loud active galaxies in the 3CR sample were found by Fanaroff and Riley to be correlated with their luminosity. We revisit this canonical ...

    • The origin of radio emission in broad absorption line quasars: Results from the LOFAR Two-metre Sky Survey 

      Morabito, L. K.; Matthews, J. H.; Best, P. N.; Gürkan, G.; Jarvis, M. J.; Prandoni, I.; Duncan, K. J.; Hardcastle, M. J.; Kunert-Bajraszewska, M.; Mechev, A. P.; Mooney, S.; Sabater, J.; Röttgering, H. J. A.; Shimwell, T. W.; Smith, D. J. B.; Tasse, C.; Williams, W. L. (2018-08-16)
      We present a study of the low-frequency radio properties of broad absorption line quasars (BALQSOs) from the LOFAR Two-metre Sky-Survey Data Release 1 (LDR1). The value-added LDR1 catalogue contains Pan-STARRS counterparts, ...

    • The WEAVE-LOFAR Survey 

      Smith, D. J. B.; Best, P. N.; Duncan, K. J.; Hatch, N. A.; Jarvis, M. J.; Röttgering, H. J. A.; Simpson, C. J.; Stott, J. P.; Cochrane, R. K.; Coppin, K. E.; Dannerbauer, H.; Davis, T. A.; Geach, J. E.; Hale, C. L.; Hardcastle, M. J.; Hatfield, P. W.; Houghton, R. C. W.; Maddox, N.; McGee, S. L.; Morabito, L.; Nisbet, D.; Pandey-Pommier, M.; Prandoni, I.; Saxena, A.; Shimwell, T. W.; Tarr, M.; Bemmel, I. van; Verma, A.; White, G. J.; Williams, W. L. (Societe Francaise d'Astronomie et d'Astrophysique, 2016-10-14)
      In these proceedings we highlight the primary scientific goals and design of the WEAVE-LOFAR survey, which will use the new WEAVE spectrograph on the 4.2m William Herschel Telescope to provide the primary source of ...